WORCESTER 
Witnesses said a large dump truck left its body up as it drove onto Route 20 tonight, taking down electrical wires, snapping utility poles, and leaving a backhoe operator trapped with live wires over his rig.

“I first saw the transformer explode,” said Steven Derosier of Worcester, who had just walked outside Foodworks in the former Big Y Plaza at Southwest Cutoff (Route 20) and Sunderland Rd.

Chris Scott of Worcester was also in the parking lot around 7:30 and said that after the explosion, he saw the dump truck with its body up in the road. The driver kept on going, Mr. Scott and Mr. Derosier said. Several other transformers blew up along Route 20, the two men said.

The two men said that right after the dump truck drove away, a backhoe operator drove by and the backhoe became entangled in the live wires hanging low across the busy road.

The men said they yelled to the backhoe operator to stay inside the cab until help arrived.

Once National Grid crews arrived and cut the power to the wires, firefighters helped the backhoe driver to safety, Mr. Scott and Mr. Derosier said.

Police briefly blocked Route 20 in both directions from Sunderland Road to the Grafton Street (Route 122) ramps. At least four utility poles appeared to be snapped or leaning along the westbound lanes of Route 20.

Later tonight, National Grid said fewer than 5 customers, on Southwest Cutoff, were without power as a result of the accident. They estimated power would be restored at 9 a.m.